JPH08333031A - Printer - Google Patents

Abstract

PURPOSE: To prevent double feed of paper sheets in case of a small remaining number of paper sheets when separation by a separation claw is selected in a printer, which can separate the paper sheets fed by either the separation claw or a wall face. CONSTITUTION: Restriction means 16k and 93 are provided to restrict a separation claw 60 so as not to allow the separation claw 60 to reach the position of the separation claw 60 in relation to a recessed portion 22f when separation by a wall face is selected by the selection mechanism 70.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to printers. More specifically, the present invention relates to the sheet feeding device, particularly to a hopper and a separating claw.

[0002]

2. Description of the Related Art As a conventional printer, as shown in FIG. 13, a printer having a hopper 1, a paper feed roller 2, a separation claw 3, a wall surface 4, and a selection mechanism (not shown) is known. There is.

A plurality of sheets P are stacked on the hopper 1 in a stacked state. Normally, the hopper 1 is capable of pressing the paper P toward the paper feed roller 2 by the urging force F of the urging means.

The paper feed roller 2 is in contact with the uppermost paper P1 of the plurality of papers P placed on the hopper 1 to rotate and can feed the paper.

The separating claw 3 is located at a corner Pc of the paper P placed on the hopper, and lightly presses the corner Pc from above.

The wall surface 4 has a sheet feeding direction (direction of arrow a).
It is located in the front and contacts the leading edge Pa of the sheet when the sheet is fed.

The selecting mechanism selects whether to separate the fed sheets by the separating claw 3 or the wall surface 4 according to the type of the sheets placed on the hopper 1. And is usually operated by the user. When the paper placed on the hopper 1 is a relatively thin paper such as plain paper, separation by the separation claw 3 is selected, and the paper placed on the hopper 1 is a relatively thick paper such as a postcard. , The separation by the wall surface 4 is selected. It should be noted that these selections are made before the paper is placed on the hopper 1.

When the separation by the separation claw 3 is selected, the separation claw 3 is in a state of gently pressing the corner portion Pc of the paper P from above as shown in FIG.

In such a state, when the paper feed roller 2 rotates and the feeding of the uppermost paper P1 in the direction of the arrow a is started, the corner Pc thereof is lightly pressed by the separating claw 3. As a result, upward bending is generated around the corner Pc. When the bending of the sheet P1 in the direction of the arrow a is increased and reaches the limit, the corner portion Pc is detached from the separation claw 3 so as to be repelled. As a result, the uppermost sheet P1 becomes the next sheet P2.
Then, only the uppermost sheet P1 is fed.

When the separation by the wall surface 4 is selected,
By the operation of the selection mechanism, the separating claw 3 is housed in the recess 1a provided at the tip corner of the hopper 1, as shown in FIG. At this time, the separation claw 3 is accommodated below the sheet mounting surface 1b of the hopper 1 so as not to become an obstacle when a relatively thick sheet PH such as a postcard is set in the hopper.

In such a state, when the paper feed roller 2 rotates and the feeding of the uppermost sheet PH1 in the direction of the arrow a is started, the leading end PHa of the sheet PH1 abuts the wall surface 4 and is curved in a concave shape. To do. This curve is the top paper PH1.
Since the tip of the next-order sheet PH2 that moves a little along with it becomes larger than the curvature caused by abutting against the wall surface 4, the highest-order sheet P1 is separated from the next-order sheet P2, and only the highest-order sheet P1 remains. Will be delivered.

That is, according to the conventional printer as described above, when printing on a relatively thin sheet, the separation claw 3 is used.
Can be fed sheet by sheet. When printing on a relatively thick sheet, the wall surface 4 can be fed sheet by sheet.

[0013]

In the above-mentioned conventional printer, the following problems occur when the separation by the separation claw 3 is selected.

That is, when the number of sheets placed on the hopper 1 becomes small (for example, a few sheets), the separating claw 3 is provided at the tip corner portion of the hopper 1, as shown in FIG. The corner portion P1c of the uppermost sheet P1 and the corner portion P2c of the secondmost sheet P2 are largely bent at the same time (before the feeding operation by the sheet feeding roller 2 is started). It will be in a state. Therefore, the paper feed roller 2
When the sheet feeding operation is started, the corner P1c of the uppermost sheet P1 and the corner P2c of the secondmost sheet P2 are simultaneously disengaged from the separating claw 3, and the uppermost sheet P1 and the next sheet P1 In some cases, so-called double feeding occurs in which the sheet P2 is fed at the same time.

An object of the present invention is to solve the above problems and to provide a printer in which double feeding of paper does not occur when separation by a separating claw is selected.

[0016]

In order to achieve the above object, a printer according to a first aspect of the present invention is a printer in which a plurality of sheets are placed in a stacked state, and a plurality of sheets placed on the hopper. A paper feed roller that comes into contact with and feeds the uppermost paper among the papers, and a corner of the paper that is placed on the hopper. If the paper is a relatively thin paper, Separation claw for separating the topmost paper from the next paper,
A wall surface for separating the uppermost sheet from the next sheet when the sheet placed on the hopper is located in front of the sheet in the feeding direction and the sheet is a relatively thick sheet; A selection mechanism for selecting separation by claw or wall surface, and a recess provided in the hopper for accommodating the separation claw below the sheet mounting surface of the hopper when separation by the wall surface is selected by the selection mechanism. And when the separation mechanism selects the separation by the separation claw, the separation claw is controlled so as not to reach the position of the separation claw with respect to the recess when the separation by the wall surface is selected by the selection mechanism. And a regulation means.

[0017]

According to the printer of the first aspect, the hopper on which a plurality of sheets of paper are placed in a stacked state and the uppermost sheet of the plurality of sheets of paper placed on the hopper are brought into contact with each other. To separate the top sheet from the next sheet when it is located at a corner of the sheet feeding roller and the sheet placed on the hopper and the sheet is a relatively thin sheet. Of the separation claw and the front of the sheet placed on the hopper in the feeding direction, and when the sheet is a relatively thick sheet, it separates the top sheet from the next sheet. Wall surface,
A selection mechanism for selecting separation by the separation claw or separation by a wall surface and a hopper provided in the hopper, and when the separation by the wall surface is selected by the selection mechanism, the separation claw is housed below the sheet mounting surface of the hopper. When the separation mechanism selects the separation claw, the top sheet of the plurality of relatively thin sheets placed on the hopper is the separation claw. Is separated from the next paper by and is fed by the paper feed roller. Further, when the separation by the wall surface is selected by the selection mechanism, the separation claw is housed in the recess provided in the hopper, and the separation claw of the highest position among the plurality of relatively thick sheets placed on the hopper is selected. The paper is separated from the next paper by the wall surface and is fed by the paper feed roller.

When separation by the separating claw is selected by the selecting mechanism, the separating claw is separated by the restricting means.
When the separation by the wall surface is selected by the selection mechanism, it is regulated so as not to reach the position located with respect to the recess.

Therefore, even when the number of relatively thin sheets placed on the hopper becomes small, the corner portions of these sheets are largely bent at the same time (before the feeding operation by the sheet feeding roller is started). It is prevented that the state becomes the restricted state.

Therefore, only when the feeding operation by the paper feed roller is started, the large deflection necessary for separating the above-mentioned paper is obtained, and the top paper is separated from the next paper. Then, only the uppermost sheet is fed.

That is, according to this printer, the double feeding of the paper is prevented when the separation by the separation claw is selected.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing the internal structure of an ink jet printer which is one embodiment of the printer according to the present invention, and FIG. 2 is a partially omitted plan view of the same.

First, an outline of this printer will be described.

In FIG. 1, reference numeral 10 denotes a printer main body, and 1
Reference numeral 1 is a case of the main body, and 20 is an automatic paper feeder incorporated in the main body 10.

The main body 10 has a paper path PP through which the paper P fed by the automatic paper feeder 20 (see P1 in FIG. 6) passes.
Along with the paper feed roller 30 and the paper feed roller 30
A pinch roller 40 that is pressed against and driven by the paper, a regulating member 50 that guides the back surface of the paper P, a carriage 52 on which an inkjet head 51 that ejects ink droplets toward the paper and prints is mounted, and a guide roller 53. A pair of discharge rollers 54 and 55, and a discharge section 56. Further, on the front surface of the main body 10, a paper discharge tray 57 for stacking the discharged paper is provided.

Paper P fed by the automatic paper feeder 20
(See P1 in FIG. 6) reaches the paper feed roller 30 via the paper path PP curved in a concave shape as a whole in FIG. 1, and the feed angle is defined by the pinch roller 40, and the paper feed roller 30 is fed out. The paper P sent out is
First, its tip is guided by the defining member 50 which also serves as a guide member, and then the back surface of the defining member 5
By being guided by 0, the distance from the inkjet head 51 is defined, and ink is ejected from the head 51 to the surface of the inkjet head 51 for printing. The printed paper P is
The sheet is discharged onto the sheet discharge tray 57 via the pair of sheet discharge rollers 54 and 55 and the discharge section 56.

Next, the details of the automatic sheet feeder 20 will be mainly described.

As shown in FIGS. 1 and 2, a main body 10 has a case 11 in which a bottom frame 12 made of a metal plate also serving as a shield plate and left and right plastic stands erected on the bottom frame 12 are provided. Side frames 13, 14
And an intermediate frame 15 made of a metal plate, which is erected on the side frames 13 and 14, and a plastic sub-frame 16 fixed in place on each of the above frames.

As shown in FIG. 3, the sub-frame 16 is integrally formed with a bottom plate 16a forming the lower part of the paper path PP, a back plate 16b, and the left and right sides of the bottom plate 16a and the back plate 16b. And side plates 16c and 16c 'that have been formed. That is, the bottom plate 16a, the back plate 16b, and the side plates 16c and 16c 'are integrally formed. A rib-shaped paper guide 16e is formed on the upper surface of the bottom plate 16a. The upper surface (inclined surface) 16f of this paper guide 16e
Forms a wall surface for separating a relatively thick sheet, which will be described later, together with the inclined surface 16g of the bottom plate 16a (see FIG. 7).

The automatic paper feeder 20 includes two paper feed rollers 2
1, a hopper 22, edge guides 23 and 23 ', a paper feed tray 24, a separation claw 60 (see FIGS. 4 and 5), and a selection mechanism 70 (see FIGS. 4 and 5). .

The paper feeding roller 21 is composed of a D-shaped roller having a straight line portion 21a and a circular arc portion 21b and having a rubber layer on its surface, and is fixed to a grooved paper feeding roller shaft 21c. . The feed roller shaft 21c is the subframe 16
Is rotatably supported by the side plates 16c, 16c 'of
A transmission mechanism 110 (see FIG. 4) that interlocks with the drive mechanism 100.
It is driven to rotate during paper feeding. In FIG. 4, 21d is an auxiliary roller.

As shown in FIG. 3, the hopper 22 has a bottom plate 22a for supporting the lower surface of the sheet, a recess 22f formed at a front end corner of the bottom plate 22a, and a front end of the bottom part 22a. Formed cam followers 22b, 22b
Similarly, triangular side plates 22c, 22c integrally formed on the lower left and right front ends of the bottom portion 22a, and a total of four pins integrally projecting laterally on the cam follower 22b and side plate 22c, respectively. 22d. And
These pins 22d and 22d are two long holes 16d formed in the side plates 16c and 16c 'of the sub-frame 16, respectively.
By engaging with the hopper 22, the hopper 22 is attached so as to be movable back and forth toward the paper feed roller 21 as shown in FIG. Hopper 22 and bottom plate 1 of subframe 16
A hopper spring 25 is provided between the hopper 22 and the sheet feeding roller 6a.
Is urged towards. Two hopper springs 25 are provided at positions corresponding to the paper feed roller 21 (see FIG. 4). As shown in FIG. 4, first cams 26, 26 for contacting the cam followers 22b and pushing down the hopper 22 against the spring force of the hopper spring 25 are provided near both ends of the paper feed roller shaft 21c. It is provided integrally. Then, as will be described later in detail, the hopper 22
Is released by the first cam 26 at the time of sheet feeding, and is pushed up by the hopper spring 25 so as to push the sheet toward the sheet feeding roller 21, and is pushed down by the first cam 26 after the sheet feeding is finished. The contact of the sheet with the roller 21 is released.

The edge guide 23 has a bottom plate 23a, a bent portion 23b provided at the tip of the bottom plate 23a, a clip portion 23c provided at the rear end of the bottom surface, and a side plate 23d. The bent portion 23b is the groove 22 of the hopper 22.
It is slidably attached to the hopper 22 by engaging with e and elastically sandwiching the clip portion 23c so as to wrap the rear portion (upper end portion) of the hopper 22.

The edge guide 23 is for guiding the left side of the paper (see FIG. 6) set on the hopper 22. The right side of the sheet is guided by the inner side surface of the other edge guide 23 'integrally formed with the bottom plate 22a of the hopper.

As shown in FIG. 1, the paper feed tray 24 can be attached to and detached from the main body 10 by inserting an insertion piece 24a formed in the lower portion thereof into an insertion hole 11a provided in the case 11 of the main body 10. The bottom surface of the sheet is supported in cooperation with the hopper 22 in the attached state.

The separation claw 60, as shown in FIGS.
It has a support plate 61 for supporting the front end (lower end) Pa of the paper P (see FIG. 6) set in the hopper 22, an arm portion 62, and a cylindrical shaft 63, which are integrally formed. Has been formed. The separation claw 60 is rotatably attached to the side plate 16c 'of the subframe by mounting the cylindrical shaft 63 on the shaft 16h protruding from the side plate 16c' of the subframe. A tension spring 64 is provided between the arm portion 62 and the side plate 16c 'of the subframe, and the separation claw 60 is always biased counterclockwise in the figure by the spring force thereof.

The selection mechanism 70 is attached to the side plate 16c 'of the sub-frame 16, as shown in FIG.

The selection mechanism 70 separates the fed sheets according to the type of the sheets placed on the hopper 22 by the separation claw 60.
It is for selecting whether to perform by the wall surfaces 16f and 16g.

As will be described in detail later, when the separation by the separation claw 60 is selected, the separation claw 60 projects upward from the bottom plate 22a of the hopper and the corner of the paper P as shown by the solid line in FIG. When it becomes possible to lightly press the portion Pc from above and separation by the wall surfaces 16f and 16g is selected, the separation claw 60 is, as shown in FIG. 7, the recess 22f provided in the bottom plate 22a. Is stored in.

The selection mechanism 70 includes an operating lever 80 and an intermediate actuating body 90.

8 and 9 are views showing the operating lever 80. FIG. 8 is a perspective view, FIG. 9 (a) is a side view, and FIG. 9 (b) is a view on arrow b in FIG. .

As shown in these figures, the operating lever 80
Is an integrally molded product made of synthetic resin, and has a substantially drum-shaped base portion 81, a shaft portion 82, a knob 83, a sloped cam 84, a set 85, and a click plate 86.

As shown in FIGS. 3 and 4, the operating lever 80 has its shaft portion 82, as shown in FIGS.
By being inserted from the inside of the side plate 16c 'into the cylindrical bearing portion 16i provided in c', the side bearing 16c 'is attached so as to be rotatable in the directions of arrows a1 and a2. In FIGS. 8 and 9, 87 is a retaining claw.

The click plate 86 is formed in a thin plate shape and has a spring property, and has recesses 86a1 and 86a2. As shown in FIG. 11, when the operation lever 80 is rotated in the direction of the arrow a1, the concave portion 86a1 engages with the projection 16j protruding on the inner surface of the side plate 16c ′ with a click feeling, As shown in FIG. 12, the operation lever 80
Is rotated in the direction of arrow a2, the concave portion 86a2 engages with the projection 16j with a click feeling.

The set element 85 is formed on the base portion 81 via the leaf spring portion 85a, and can be swung in the directions of arrows b1 and b2 in FIG. 9A due to the flexibility of the leaf spring portion 85a. is there.

The operation of the slope cam 84 and the set 85 will be described later.

FIG. 10 is a view showing the intermediate operating body 90.
(A) is a front view (right side view in FIG. 4, etc.), (b) is a left side view, (c) is a right side view, (d) is a bottom view, (e).
Is a rear view.

The intermediate actuating body 90 is an integrally molded product made of synthetic resin, and has a cylindrical base portion 91 and a fan-shaped cam follower portion 92.
It has an arm part 93 and a claw part 94.

The intermediate actuating body 90 has a cylindrical base portion 91,
As shown in FIGS. 4 and 5, the separation claw 60 is mounted on the cylindrical shaft 63. The cylindrical shaft 63 is formed with a ridge 63 a, and the ridge 63 a is formed on the inner surface of the cylindrical base 91.
Since the concave groove 91a that engages with the intermediate working body 90 is formed, the intermediate actuating body 90 is non-rotatably and slidably mounted on the tubular shaft 63 of the separating claw 60.

In FIG. 4, 71 is a cover made of sheet metal, and the side plate 16 'of the sub-frame 16 is fixed by screws 72.
Be attached to. A compression spring 73 is provided between the cover 71 and the intermediate actuating body 90.
The intermediate actuating body 90 is constantly urged in the direction of arrow X1 in FIGS.

The cam follower portion 92 can come into contact with the sloped cam 84 of the operation lever described above. In FIG.
The arc surface 92a is a contact surface with the slope cam 84.

The tip portion 93a of the arm portion 93 has a shape shown in FIGS.
As shown in FIG. 7, it can be engaged with and disengaged from a protruding stopper 16k formed on the outer side portion of the side plate 16c 'of the sub-frame 16. In the present embodiment, the stopper 16k and the arm portion 93 constitute a regulating means. The arm portion 93 also serves as a cam follower. As shown in FIG. 4, a plate-shaped second cam 27 is integrally formed on the paper feed roller shaft 21c, and a substantially arc-shaped outer peripheral surface of the arm portion 93 is provided with respect to the cam surface 27a. 93b can be contact | abutted (refer FIG. 6).

The claw portion 94 can be engaged with and disengaged from the set element 85 of the operation lever 80 described above.

The operation of the automatic paper feeder 20 as described above is as follows.

(I) When the paper placed on the hopper 22 is a relatively thin paper such as plain paper In this case, the operation lever 80 is rotated in the direction of arrow a1 by the user and the separating claw 60 is moved. Is selected.

When the operation lever 80 is rotated in the direction of arrow a1, as shown in FIG. 11, the slope cam 84 of the operation lever comes into contact with the arcuate surface 92a of the cam follower portion 92 of the intermediate actuating body 90. It will be in the released state. As a result, in the intermediate actuating body 90, due to the action of the compression spring 73, as shown in FIG.
It is in a state where it has moved to a position where it can engage with 6k. At this point in time, as shown by the phantom line in FIG.
The tip 93a of No. 3 is not engaged with the stopper 16k.
That is, the stopper 16k
Is only in a position.

In such a state, the following paper feeding operation is performed.

(A) When the printer is in the standby state, as shown in FIG. 6, the paper feed roller 21 is stopped and its linear portion 21a faces the paper P on the hopper 22.

The first cam 26 on the paper feed roller 21c is a cam follower 2 of the hopper 22, as shown by a phantom line in FIG.
2b, and pushes down the hopper 22 against the biasing force of the hopper spring 25 (see FIG. 1).

The second cam 27 contacts the outer peripheral surface 93b of the arm portion 93 of the intermediate actuating body 90, and pushes up the intermediate actuating body 90, that is, the separation claw 60 in the clockwise direction against the urging force of the tension spring 64. 6 to rotate the linear portion 21 of the paper feed roller 21 as indicated by an imaginary line 60 ′ in FIG.
It is located above a.

Therefore, in such a state,
The plurality of sheets P can be easily set on the hopper 22 by inserting them from above.

(B) When the paper feed command signal is output from the control unit (not shown) of the printer, the paper feed roller 21 is moved to the position shown in FIG.
Rotate in the direction of the arrow. As a result, the first cam 26 and the second cam 27 also rotate in the same direction. As the first cam 26 rotates, the contact of the hopper 22 with the cam follower 22b is released, and the hopper 22 attaches the sheet P toward the sheet feed roller 21 by the urging force of the hopper spring 25, as shown by the solid line in FIG. Energize. Further, the rotation of the second cam 27 causes the outer peripheral surface 9 of the arm portion 93 of the intermediate actuating body 90.
The contact with 3b is released, and the intermediate actuating body 90, that is, the separating claw 60 is rotated counterclockwise by the action of the tension spring 64. As a result, the separation claw 60 lightly presses the corner portion Pc of the sheet from above by the urging force of the tension spring 64, as shown by the solid line in FIG.

As described above, since the uppermost sheet P1 comes into contact with the circular arc portion 21b due to the rotation of the sheet feeding roller 21, and when the feeding in the direction of the arrow a is started, the corner thereof is Since the part Pc is lightly pressed by the separation claw 60, a bending that rises upward is generated around the corner part Pc, and as the sheet P1 moves in the direction of the arrow a, the bending becomes large and reaches the limit. When this is done, the corner portion Pc is detached from the separation claw 60 so as to be repelled. As a result, the uppermost paper P1 is separated from the next paper P2, and only the uppermost paper P1 is fed toward the paper feed roller 30.

The fed paper is printed by the head 51 as described above, and then discharged.

It should be noted that when the paper feed roller 21 rotates just once, it returns to the above-mentioned state (a). 1 of the paper feed roller 21
The rotation is performed by the one-rotation clutch incorporated in the transmission mechanism 110 (see FIG. 4) driven by the drive mechanism 100 described above.

(C) When the sheets are sequentially fed as described above and the number of sheets is reduced, the position of the separation claw 60 at the time of sheet feeding is sequentially moved so as to approach the hopper 22 accordingly. Go on. Then, when the remaining number becomes small (for example, 2 or 3), the separation claw 60 tries to enter the recess 22f of the hopper as shown in FIG.
At this time, as shown in FIG. 5 and FIG.
The tip portion 93a of the zero arm portion contacts the stopper 16k.
As a result, the intermediate operating body 90 rotates counterclockwise,
That is, the counterclockwise rotation of the separation claw 60 is restricted,
As shown in phantom line 60 ″ in FIG. 6 and FIG. 11, the separation claw 60 is located at the position relative to the recess 22f when the separation by the wall surfaces 16g and 16f is selected by the selection mechanism 70 (see FIG. (See FIG. 12) and stops at a position that does not reach (see FIG. 11B and FIG. 12B).

Therefore, even when the number of relatively thin sheets P placed on the hopper 22 is reduced, the corners of these sheets P are preliminarily simultaneously (before the feeding operation by the sheet feeding roller 21 is started. ) It is possible to prevent the state of being greatly bent (see FIG. 11B).

Therefore, the large deflection necessary for separating the above-described sheets is obtained only when the feeding operation by the sheet feed roller 21 is started, and the top sheet P1 is the next sheet. Therefore, only the uppermost paper is fed.

That is, according to this printer, the double feeding of the paper is prevented when the separation by the separation claw 60 is selected.

(Ii) When the paper placed on the hopper 22 is a relatively thick paper such as a postcard In this case, the user operates the operation lever 80 in the direction of arrow a2 to move the wall surfaces 16g and 16f. Is selected.

When the operation lever 80 is rotated in the direction of arrow a2, the sloped cam 84 of the operation lever causes the intermediate actuator 90 to move.
5 and the intermediate actuating body 90 resists the biasing force of the compression spring 73 and the arrow X in FIG.
It is pushed in two directions. As a result, the tip 93a of the arm portion 93 moves to a lateral position where it cannot engage with the stopper 16k, and the outer peripheral surface 93b of the arm portion 93 moves to the second position.
It comes off from the cam 27 to the side. Therefore, the separation claw 60
Is rotated counterclockwise by the action of the tension spring 64, and is brought into a state of being accommodated in the recess 22f so as to come into contact with the inner surface of the recess 22f of the hopper, as shown in FIG. At this time, the separation claw 60 is housed below the sheet mounting surface 22g of the hopper 22 so that a relatively thick sheet PH such as a postcard is not obstructed when being set in the hopper as shown in FIG. It will be in a state of being

FIG. 12 shows a state in which the operating lever 80 is fully turned in the direction of arrow a2. In this state,
Arc surface 92a of the cam follower portion 92 of the intermediate operating body 90
Comes into contact with a flat surface portion 84a connected to the inclined cam 84 of the operating lever, and the movement of the intermediate actuating body 90 in the arrow X1 direction is prevented.

In such a state, the following paper feeding operation is performed.

(A) When the printer is in the standby state, as shown in FIG. 7, the paper feed roller 21 is stopped, and the linear portion 21a thereof faces the relatively thick paper PH on the hopper 22. is there.

The first cam 26 on the paper feed roller 21c is a cam follower 2 of the hopper 22, as shown by a phantom line in FIG.
2b, and pushes down the hopper 22 against the biasing force of the hopper spring 25.

Therefore, in such a state,
It can be easily set by inserting a plurality of sheets PH from above.

(B) When the paper feed command signal is output by the control unit (not shown) of the printer, the paper feed roller 21 is moved to the position shown in FIG.
Rotate in the direction of the arrow. As a result, the first cam 26 also rotates, and the contact of the hopper 22 with the cam follower 22b is released, and the hopper 22 applies the paper PH to the paper feed roller 21 as shown by the solid line in FIG.
Urge towards.

As described above, when the paper feed roller 21 is rotated, the arcuate portion 21b is brought into contact with the topmost sheet PH1 and the feeding in the direction of the arrow a is started.
The tip PHa is curved in a concave shape by contacting the wall surfaces 16g and 16f. This curve is the top paper PH1.
Since the front end of the next-order sheet PH2 that moves a little along with it becomes larger than the curvature caused by contacting the wall surfaces 16g and 16f, the top-most sheet PH1 is separated from the next-order sheet PH2 and the top-most sheet PH1 Only the paper is fed toward the paper feed roller 30.

The fed paper is printed by the head 51 as described above, and then discharged.

(Iii) Then, in order to print again on a relatively thin sheet, the operation lever 80 is moved from the state shown in FIG.
Is rotated in the direction of the arrow a1, the arcuate surface 92a of the cam follower portion 92 of the intermediate actuating body 90 comes off the flat surface portion 84a connected to the sloped cam 84 of the operation lever and comes into contact with the sloped cam 84 to rotate the operation lever 80. The intermediate working body 90 moves in the direction of the arrow X1 along with the movement.

When the set element 85 comes into contact with the claw 94 of the intermediate actuating body 90 as the operation lever 80 rotates, the set element 85 bends the leaf spring portion 85a in the direction of arrow b2 and the set element 85 claws 94. Is pushed, and the intermediate actuating body 90 is rotated in the direction of arrow c in FIG. 12 against the biasing force of the tension spring 64. When the intermediate actuating body 90 rotates in the direction of arrow c in FIG. 12, the set element 85 returns to the original position by the action of the leaf spring portion 85a, and then the leaf spring portion 85a.
While bending in the opposite direction, it swings in the direction of the arrow b1 to get over the claw 94. This releases the engagement with the claw 94,
Therefore, the intermediate actuating body 90 is rotated counterclockwise (the direction opposite to the arrow c direction) by the action of the tension spring 90. At this time, the intermediate actuating body 90 has already been moved in the arrow X1 direction as described above. The outer peripheral surface 93b of the arm portion 93 is positioned above the second cam 27 by being moved to. Therefore, the intermediate operating body 9 when the engagement between the set element 85 and the claw 94 is released.
The counterclockwise rotation of 0 (the direction opposite to the arrow c direction)
The outer peripheral surface 93b of the arm portion 93 is prevented from coming into contact with the second cam 27, and the state shown in FIG. 6 (states (i) and (a) above) is obtained. In other words, the set element 85 reliably mounts the arm portion 93 of the intermediate actuating body 90 on the second cam 27 when the separation by the wall surface is switched to the separation by the separation claw. It can be said that it is for making.

As described above, according to this printer, when printing on relatively thin paper, it is possible to feed the sheets one by one by the separating claw 60, and when printing on relatively thick paper. It is possible to feed the sheets one by one by the wall surfaces 16g and 16f.

The sheet feeding by the separating claw 60 one by one is surely performed even when the number of sheets on the hopper 22 becomes small.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be appropriately made within the scope of the gist of the present invention.

[0086]

According to the present invention, when the separation by the separation claw is selected, the double feeding of the sheets is prevented.

[0087]

[Brief description of drawings]

FIG. 1 is a side sectional view showing an internal structure of an inkjet printer which is an embodiment of a printer according to the present invention.

FIG. 2 is a partially omitted plan view of the same.

FIG. 3 is an exploded perspective view mainly showing a subframe and a hopper.

FIG. 4 is an exploded perspective view mainly showing a selection mechanism.

FIG. 5 is a schematic perspective view showing a main part of this embodiment.

6 is a partially enlarged view of FIG. 1, which is an operation explanatory view.

7 is a partially enlarged view of FIG. 1, which is an operation explanatory view.

FIG. 8 is a perspective view of an operation lever.

FIG. 9 is a view showing an operation lever, (a) is a side view,
(B) is a view on arrow b in FIG.

10A and 10B are diagrams showing an intermediate actuating body, in which FIG. 10A is a front view (right side view in FIG. 4, etc.), FIG. 10B is a left side view, FIG. 10C is a right side view, and FIG. , (E) is a rear view.

FIG. 11 is an operation explanatory view.

FIG. 12 is an operation explanatory view.

13A, 13B and 13C are explanatory views of a conventional technique, and FIG. 13B is a sectional view taken along line bb in FIG. 13A.

14A is an explanatory diagram of a conventional technique, and FIG. 14B is a cross-sectional view taken along the line bb in FIG. 14A.

[Explanation of symbols]

 P Relatively thin paper Pc Corner portion PH Relatively thick paper 16f, 16g Wall surface 16k Stopper (regulating means) 21 Paper feeding roller 22 Hopper 22f Recess 60 Separation claw 70 Selection mechanism 93 Arm portion (regulating means)

Claims (1)

[Claims] 1. A hopper on which a plurality of sheets of paper are placed in a stacked state, and a paper feed roller for contacting and feeding the uppermost sheet of the plurality of sheets of paper placed on the hopper. A separation claw located at a corner of a sheet placed on the hopper and separating the top sheet from the next sheet when the sheet is a relatively thin sheet; A wall surface for separating the uppermost paper from the next paper when the paper is relatively thick, which is located in front of the paper placed on the hopper in the feeding direction, and the separation claw. Selection mechanism for selecting the separation by the wall surface or the wall surface, and a recess provided in the hopper for accommodating the separation claw below the sheet mounting surface of the hopper when the selection mechanism selects the separation by the wall surface. And when separation by the separation claw is selected by the selection mechanism Further, the separation claw is provided with a restriction unit that restricts the separation claw from reaching the position of the separation claw with respect to the recess when the separation by the wall surface is selected by the selection mechanism.